管道焊口间隙量与错边量的激光视觉检测

Laser visual measurement for gap values and misalignment values of pipeline welding groove

提出了一种长输管线焊口组对间隙量、错边量的激光视觉检测方法.首先,搭建了一套可实现圆周焊口轮廓激光视觉自动检测的计算机系统.通过对采集的激光视觉图像分析,发现了管道焊口间隙量、错边量与激光条纹断点、拐点等图像特征间的相关关系.其次,将提取的条纹图像通过骨骼化的形态学处理,得到了单一像素宽度的细化条纹.采用亚像素轮廓坐标检测算法,获得了条纹上离散点的像素坐标.最后,基于获取的条纹拐点、断点像素坐标和几何对应关系,建立了间隙量与错边量的求取算法.实际验证结果表明,基于激光条纹特征点像素坐标获取间隙量与错边量的激光视觉检测方法是可行的.测量结果可满足焊口组对质量评判的需求.

A laser visual measurement method for values of the gap and misalignment is proposed, when the welding grooves are assembled between pipelines. Firstly, a computer system is designed to realize the automatic detection for the profile of welding grooves. Through the analysis of the collected laser vision images, it is found that the correlative relationship between the values of gap and misalignment and the break point and inflection point of laser stripes. Secondly,the extracted stripe images are processed by skeletal morphology to obtain refined stripes with a single pixel width.The same time, using the sub-pixel contour coordinate detection algorithm, the pixel coordinates of the discrete points on the stripes are obtained. Finally, based on the abovementioned correlative relationship, the algorithms for the gap values and the misalignment values are established. The actual verification shows that it is feasible to measure values of the gap and misalignment based on the pixel coordinates of feature points in laser stripe, the measurement results can meet the needs of quality assessment in the process of the weld groove assembly